The following information is a Web Extra from the pages of Farm Journal. It corresponds with the article "The Secrets of Sulfur" You can find the article in the Farm Journal September issue.
Sulfur in Acid Rain
Although acid rain, which deposits sulfur on fields, has been reduced since the Clean Air Act was passed in 1972, it still exists.
“The northeastern United States has the highest sulfur deposits, ranging from 25 lb. to 40 lb per acre per year,” says Farm Journal Staff Agronomist Ken Ferrie. “In contrast, the Western Plains receive only 1.8 lb. to 4½ lb. of sulfur per acre per year. As a result, the need to apply supplemental sulfur depends on where you live.”
Acid rain can be beneficial in moderation, but disastrous at high levels, Ferrie notes. “Typical rain has a pH of 5.6 to 7,” Ferrie says. “The pH of acid rain can drop below 4.0. Acid rain is what causes old grave stones to deteriorate until you can no longer read them. Deforestation from acid rain remains a very serious issue in Third World countries.”
Facts About Sulfur
- Sulfur is found in all living organisms.
- Plants contain about as much sulfur as phosphorus (0.2% to 0.5% of dry matter).
- In nature sulfur can be found as the pure element, as sulfide gas and as sulfate minerals.
- Sulfur, contained in the protein keratin, gives strength to hair and feathers, and contributes to the odor when they are burned.
- Sulfur is responsible for the odor in onions that makes you cry.
- Sulfur is the tenth most abundant element in the universe.
- Sulfur is used to make black powder (old-fashioned gunpowder), in fungicides and insecticides and in the manufacture of matches and vulcanized rubber.
- The sources of the inorganic sulfur you apply are mainly the byproducts of cleaning sulfur out of coal, crude oil or natural gas.
- The Bible refers to sulfur as brimstone.
Sulfur’s role in plants:
- Producing lignin and pectin
- Producing chlorophyll
- Metabolizing nitrogen
Sulfur removal per bushel of grain:
- .08 lb. by the grain
- .09 lb. by the by the stalk
Sulfur removal in 200 bushels: 34 lb. of elemental sulfur, or 102 lbs of sulfate
Sulfur Management Tips
- Account for the acidity in your sulfur sources.
- Don’t apply sulfate sulfur in the fall to highly leachable soils.
- Sulfur uptake must be early in the spring.
- Elemental sulfur may not respond fast enough for spring application.
- Maintain the correct ratio between nitrogen and sulfur.
- Use tissue testing to check the ratio of nitrogen and sulfur in the plant.
- Corn requires about 1 lb. of sulfur per 14 lb. of available nitrogen.
- Organic matter is the main supplier of sulfur.
- Apply more sulfur if organic matter content is less than 3%.
- Apply more sulfur if soils are alkaline (above 7.5 pH) or acid (below 5.9 pH).
- With acid soils, applying lime is a better solution than applying more sulfur.